Translocation Translocation is the process within plants that functions to deliver nutrients and other molecules over long distances throughout the organism.
Plant Physiology Biology - Dr. Definition Solute transport in plants, translocation, primarily occurs in the phloem, but it can occur in the xylem.
See table on overhead. Substances move at different rates depending on matrix effects, metabolic needs, etc. Solute Transport in the Phloem Phloem is difficult to study in plants because: Phloem is the primary transport tissue for photosynthates photoassimilates, or simply stated - organic materials.
Radiotracer studies in which leaves are briefly exposed to 14C-labeled carbon dioxide show that radioactive photosynthates are localized in the phloem. Phloem-feeding aphids stick their hollow, syringe-like stylet directly into phloem cells.
Thus, aphid studies demonstrate that the phloem is under pressure. Further, the honeydew can be collected and we can identify its composition. Better yet, after anaesthetizing the aphid with CO2 the body is severed from the stylet leaving a miniature spile tapped directly into the phloem.
Phloem Content see table on overhead Analysis - early studies to determine the content of the phloem involved cutting into the plant and analyzing the contents of the sap that was recovered.
Aphid studies described above helped to solve this problem. Phloem is rich in: The major organic transport materials are sucrose, stachyose sucrose-galraffinose stachyose-gal. These are excellent choices for transport materials for two reasons: Thus, sucrose is a good transport form that provides a high energy, yet stable packet of energy; 2.
These compounds serve to transport "nitrogen"; 3. ATP, hormones, sugar alcohols like sorbitol apple, pear, prune and mannitol mangrove, oliveand an assortment of other organic materials; and 4.
Inorganic substances including magnesium and potassium.
Direction of phloem transport Information derived from several experiments; check out the Phloem Case Studies. These experiments showed the accumulation of material above the girdle, and that carbohydrates were not translocated below the girdle.
Thus, plants transport substances in the phloem downward toward the roots. See data on overheads.• Water is critical for plants functionally and structurally • Water relations drove plant evolution • Water relations are fundamental to plant growth and function • For every gram of organic matter made by the plant, approximately g of water is absorbed by the roots, transported through the plant body and lost to the atmosphere.5/5(7).
In the xylem there is a high water potential, water will move by osmosis from a region of high water potential to a region of low water potential in the sieve tube down a water potential gradient.
The driving force for water entry to the phloem is the osmotic gradient created by the accumulation of sugar. In this article we will discuss about the Flow of Source and Sink in Phloem Translocation.
It is the long distance movement of organic substances from the source or supply end (region of manufacture or storage) to the region of utilization or sink. In this review, we summarize the current understanding of As transport in plants, with an emphasis on As uptake, mechanisms of As resistance and the long-distance translocation of As, especially the accumulation of As in grains through phloem-mediated transport.
Translocation is the movement of materials from leaves to other tissues throughout the plant. Plants produce carbohydrates (sugars) in their leaves by photosynthesis, but nonphotosynthetic parts of the plant also require carbohydrates and other organic and nonorganic materials.
In vascular plants, phloem This transport process is called translocation. In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Greek word While movement of water and minerals through the xylem is driven by negative pressures (tension).